Carbon-supported Pd–Pt cathode electrocatalysts for proton exchange membrane fuel cells

A series of carbon-supported Pd–Pt alloy (Pd–Pt/C) catalysts for oxygen reduction reaction (ORR) with low-platinum content are synthesized via a modified sodium borohydride reduction method. The structure of as-prepared catalysts is characterized by powder X-ray diffraction (XRD) and transmission electron microscope (TEM) measurements. The prepared Pd–Pt/C catalysts with alloy form show face-centered-cubic (FCC) structure. The metal particles of Pd–Pt/C catalysts with mean size of around 4–5 nm are uniformly dispersed on the carbon support. The electrocatalytic activities for ORR of these catalysts are investigated by rotating disk electrode (RDE), cyclic voltammetry (CV), single cell measurements and electrochemical impedance spectra (EIS) measurements. The results suggest that the electrocatalytic activities of Pd–Pt/C catalysts with low platinum are comparable to that of the commercial Pt/C with the same metal loading. The maximum power density of MEA with a Pd–Pt/C catalyst, the Pd/Pt mass ratio of which is 7:3, is about 1040 mW cm−2.

Research highlights▶ We synthesized low-platinum carbon-supported Pd–Pt alloy (Pd–Pt/C) catalysts. ▶ The metal nanoparticle of these catalyst are uniformly dispersed on the carbon support. ▶ The electrocatalytic activities of Pd–Pt/C with low Pt are similar to that of Pt/C. ▶ The use of these catalysts is beneficial to substitute the Pt partly with Pd.